49ers have several draft options at right guard

Midwestern State’s Amini Silatolu is an unpolished, freakishly gifted prospect who will need to learn a new position in the NFL.

In other words, the Division II All-American from Tracy sounds like a classic, modern-day 49ers draft pick.

A year after San Francisco’s stellar draft opened with the selections of defensive end Aldon Smith, quarterback Colin Kaepernick and cornerback Chris Culliver – ultra-talented players who required some serious coaching – the 49ers could be eyeing Silatolu with the No. 30 pick in the draft.

The possible pairing makes sense given San Francisco’s unsettled right-guard position and Silatolu’s background.

A left tackle in college, Silatolu, 6-foot-4 and 313 pounds, possesses a notable nasty streak, excellent agility and a 31 1/2-inch vertical leap. He dominated the competition at San Joaquin Delta College and Midwestern State in Wichita Falls, Texas, schools he attended because of academic problems.

His position coach at Midwestern State, Brian Natkin, says NFL scouts have made comparisons to Larry Allen, a retired 11-time Pro Bowl guard who played at Division II Sonoma State. Former 49ers defensive lineman Pierce Holt, a defensive assistant at Angelo State, which plays Midwestern State in the Lone Star Conference, says Silatolu looks the part.

“The thing that I like about him from what I saw on film is, he’s a strong run blocker and he’s got good feet for pass protection,” said Holt, 50, who played eight seasons with the 49ers and Falcons. “… His footwork is exceptional, and he’s certainly strong enough.”

The obvious question, of course, is how Silatolu will fare when facing stiffer competition. Adding to the mystery: He couldn’t play against Division I competition at the Senior Bowl in January because of a pulled hamstring.

If the 49ers do target a guard in the first round, Wisconsin’s Kevin Zeitler is a safer option who won’t require a position change and will be more likely to start as a rookie. Zeitler played in a power-run offense that has produced several successful NFL offensive linemen. He also played against top competition in the Big Ten. Silatolu played the likes of Tarleton State.

“It just comes down to if they are willing to roll the dice a little bit on the long-term potential of Silatolu,” Rang said. “Or are they more inclined to go with a relatively sure thing who will make an immediate impact, but doesn’t necessarily possess the upside?”

Given the 49ers’ recent history, Silatolu would seem to be the choice.

In 2010, the 49ers hit on the No. 17 pick by selecting left guard Mike Iupati, who dominated lesser competition at Idaho.

Last year, Smith, Kaepernick and Culliver each fit the boom-or-bust-pick mold: prospects blessed with rare physical gifts and surrounded by question marks.

Smith, who has an 84-inch wingspan, left school after an injury-marred sophomore season at Missouri that included so-so production. Kaepernick, who has a Howitzer arm and rushed for 4,009 yards at Nevada, had a much-scrutinized release and piled up record-setting stats against lesser competition in the WAC. Culliver, who ran a 4.4-second 40-yard dash, began his college career as a wide receiver and finished as a safety.

The 49ers moved Culliver to cornerback, making him one of their four draftees who played a different position as a rookie. (Smith was listed as a linebacker, but lined up primarily at defensive end, which he played at Missouri.) The most striking position switch was seventh-round pick Bruce Miller, who became a starter at fullback after playing defensive end in college.

A year later, Silatolu could be the latest draftee who will arrive with questions the 49ers believe they can answer.

“I think the San Francisco coaching staff is feeling pretty confident that they can teach their system to guys, and justifiably so,” Rang said. “… For the 49ers, I think Silatolu is very intriguing because he has the talent level to be a Pro Bowl kind of a player. At the same time, there is some boom-or-bust factor there.”

On guards

The 49ers enter the NFL draft without a clear starter at right guard, their only unsettled position. If they address the position with the No. 30 pick, or trade up, here are their likely candidates:

David DeCastro, Stanford: He’s unquestionably the best of the bunch. In fact, he’s so good the 49ers will have to trade up if they want to reunite Jim Harbaugh with the featured run blocker in Stanford’s smashmouth attack. A three-year starter, DeCastro is expected to be off the board by the middle of the first round.

Kevin Zeitler, Wisconsin: CBS Sports draft analyst Rob Rang terms Zeitler “arguably the safest player that no one seems to be talking about as a first-round guy.” A three-year starter, Zeitler will be the latest in a long line of Badgers offensive linemen in the NFL, a list that includes Gabe Carimi (Bears), John Moffitt (Seahawks), Bill Nagy (Cowboys) and Joe Thomas (Browns).

Peter Konz, Wisconsin: Speaking of Wisconsin offensive linemen, Konz was a center in college who could slide to guard in the NFL. Worth noting that the 49ers will have trusted scouting reports on the Wisconsin linemen: Paul Chryst, the brother of 49ers quarterbacks coach Geep Chryst, was the Badgers’ offensive coordinator during the careers of Zeitler and Konz.